1. Field of the Invention
The present invention relates to an offset compensation circuit as well as a drive circuit with offset-compensation capability and a liquid-crystal display device that use the offset compensation circuit. In particular, the present invention relates to an offset compensation circuit compensating for an offset voltage of a drive circuit which outputs a potential according to an input potential as well as a drive circuit with offset-compensation capability and a liquid-crystal display device using the offset compensation circuit.
2. Description of the Background Art
An offset compensation circuit canceling an offset voltage of a drive circuit has been proposed. The offset compensation circuit charges a capacitor to the offset voltage and connects the capacitor to an input node of the drive circuit so as to compensate for the offset voltage (see for example Japanese Patent Laying-Open No. 2000-114889).
The conventional offset compensation circuit, however, encounters a problem that it cannot accurately compensate for the offset voltage since the voltage of the capacitor is lost due to the influence of a parasitic capacitor of the input node of the drive circuit.
Although the voltage loss could be reduced by making the capacitance value of the capacitor sufficiently greater than that of the parasitic capacitor, a resultant need for increase of the area of the capacitor causes the area occupied by the offset compensation circuit to expand. If the offset compensation circuit is employed for a data-line drive circuit of a liquid-crystal display device, many offset compensation circuits are necessary so that the problem would become particularly severe.